NASA may go back to the future and use Saturn V engines on Mars rocket

View full sizeVon Braun stands at the Saturn 5 static display at the U.S. Space and Rocket Center, in the background is the five huge Rocketdyne F1 engines developed for the Saturn V rocket that took Americans to the moon.

HUNTSVILLE, Alabama -- A Huntsville company competing to power NASA's new heavy-lift rocket to Mars says the best engines for the job may be the same massive F-1 engines that lifted the Saturn V Apollo rockets nearly 50 years ago.

"We know you need a lot of thrust," Dynetics Inc. Vice President Steve Cook said last week, "and if you want to do it affordably, we think you need a liquid (fueled motor). So, now you say, 'What engines do I have?'"

"Well, we've already done this before," Cook said to answer his own question. "You had 13 fully successful Apollo flights with never an in-flight failure of, guess what, the F-1 engine."

Dynetics is negotiating a contract with NASA to find out if a modernized version of the F-1 really makes sense. If NASA awards Dynetics the contract as expected, it will also lead to construction of the biggest piece of rocket hardware in Huntsville since Apollo. "The point here is keeping the rocket in the Rocket City and taking it to a whole other level," Cook said.

NASA plans to use solid rocket boosters for the first flights of its 70-metric-ton rocket called the Space Launch System. But it is letting the aerospace industry compete over which boosters will be used on the later 130-metric-ton version.

Companies will first spend 30 months on what NASA calls "risk-reduction" tasks. That means building test hardware and doing engineering demonstrations to show NASA they've accounted for the foreseeable risks in their ideas.

"History will tell you that where your costs go up dramatically in development is if there's a big risk out there that you haven't been able to mitigate down to where you can say, 'I understand that,'" Cook said.

With NASA's mantra for the new rocket being "performance, reliability and affordability," risk-reduction now is key. Hitting an expensive snag later could prove fatal to the program, given the mood in Congress about government spending.

The first of Dynetics' demonstrations involves the F-1 engine. The company's basic idea for the new booster is putting two modern versions of a liquid-fueled F-1 engine on tanks and strapping two of the tank sets to the heavy-lift rocket. That's two boosters, four F-1 engines and more than 7 million pounds of thrust.

"The F-1 was not designed to be a low-cost engine," Cook said. "It was designed to get you to the moon. Whatever it took to get you to the moon." But with modern methods and technologies, Cook said Dynetics believes it can build cheaper, but powerful and reliable F-1s.

Team partner Pratt & Whitney Rocketdyne has three modified F-1 turbopumps in storage, Cook said. Those massive pumps are what fed the kerosene and oxygen fuel mixture to "feed the beast," as Cook called the F-1. "We're going to fire that turbopump," he said.

The turbopump is fed, in turn, by a gas generator. "Think of it as a 20,000 pound rocket engine strapped to the side of the F-1 that gets those turbopumps going," Cook said.

Dynetics will test a lower-cost version of a gas generator and add it to the turbopump to create what's called a power pack. Add a combustion chamber and a nozzle later and you basically have a rocket engine, Cook said.

Dynetics won't actually assemble and fire an F-1 unless NASA lets it go forward into the booster development phase. That's not a given. Other companies are pursuing other booster options, and NASA will have to choose. "But in the development phase, we could fire an F-1 in a few months," Cook said.

Risk-reduction task No. 2 is building the 17-inch diameter fuel and oxygen lines to feed the F-1 engine. Valves and lines like those and the systems to run them haven't been built in America since Apollo, Cook said, but Dynetics will build all three in Huntsville in the next 30 months, if it gets the NASA contract as expected.

Risk-reduction task No. 3 is building tanks to hold the propellants. Dynetics plans to do that in Huntsville using its new high-bay development facility and $90 million in modern welding tools at Marshall Space Flight Center. Those tools were added for the now-canceled Constellation rocket program.

"The tooling was set up for something 18 feet in diameter," Cook said. "It turns out that the physics and the requirements of the Vehicle Assembly Building (at Kennedy Space Center in Florida) mean you'd really like to have a booster that's 18 feet in diameter."

It also takes a tank that big to hold the nearly 2 million pounds of propellant each booster system requires.

Dynetics plans to build a test tank in Huntsville 18 feet wide and 60 feet long (shorter than the final version) and take it by barge to the company's test facility in Iuka, Miss. for deep-freeze testing.

The tank "will be the biggest structure built for a launch vehicle in Huntsville since Saturn Apollo," Cook said. "We are going to prove that we can build a very robust stage out of aluminum using the facilities at Marshall and in research park."

Will Huntsville again feel the rumble and hear the thunder of an F-1 test as it did in Apollo's glory days? It won't happen. NASA tests its rocket engines at the Stennis Space Center in Mississippi these days.

But if NASA does choose to go back to the future and use new F-1s, expect a lot of traffic from Huntsville to Stennis. Fire an F-1 rocket engine, and anyone who can get past the gate won't miss that.